Submission #882355

#	Time	Username	Problem	Language	Result	Execution time	Memory
882355		pirhosig	Finding Routers (IOI20_routers)	C++17	100 / 100	2 ms	856 KiB

routers

#include "routers.h"
#include <bits/stdc++.h>
using namespace std;



int cqu(unordered_map<int, int>& cac, int val) {
    if (cac.find(val) == cac.end()) cac[val] = use_detector(val);
    return cac.at(val);
}



int solve(unordered_map<int, int>& cac, int low, int upp, int val) {
    while (low < upp) {
        int mid = (low + upp + 1) / 2;
        int qres = cqu(cac, mid);
        // cerr << mid << endl;
        if (qres >= val) upp = mid - 1;
        else low = mid;
    }
    return low;
}



vector<int> find_routers(int l, int n, int q) {
    vector<int> ans;
    ans.push_back(0);
    unordered_map<int, int> cac;
    if (n == 2) {
        int res = solve(cac, 0, l, 1);
        ans.push_back(res * 2);
        return ans;
    }
    vector<pair<int, int>> close;
    close.push_back({0, 0});
    constexpr int jump = 60;
    for (int i = jump; i < l; i += jump) close.push_back({cqu(cac, i), i});
    close.push_back({cqu(cac, l), l});
    for (int i = 1; i < n; ++i) {
        auto upp = lower_bound(close.begin(), close.end(), make_pair(i, 0));
        auto low = prev(upp);
        int res = solve(cac, low->second, upp->second, i);
        ans.push_back(2 * res - ans.back());
    }
    return ans;
}

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 40 / 40